Photo story: Undulate rays from Dorset to the Med

Date posted:
12 March 2018

Undulate rays Raja undulata are an endangered species. But despite that label they’ve been reported as abundant in patches along the English Channel including Sussex, Poole, around the Isle of Wight, Lyme Bay, the Channel Islands and further south in the Mediterranean Sea.

The undulate ray skeleton is made of cartilage and they have rounded flat bodies which can grow up to 1 metre in length. Their very thin whip-like tail can grow as long as their bodies and their skin has a pattern of swirly brown stripes and yellow and white spots. They can weigh up to nine kilos and to keep predators at bay they have spiny backs and tails and a prickly underbelly. Undulates feed on crustaceans and live at depths of up to 30 metres on sandy and soft mud seabeds.

The main threat to undulate rays is bycatch in mixed fisheries, but they’re thought to be quite resilient to capture and release, and so if they are discarded alive, survival rates are thought to be high. Recreational divers, Martin and Sheilah Openshaw, have had almost 100 encounters with undulate rays near Kimmeridge Ledges, a series of shallow ledges reaching out to sea about a mile off Dorset’s Isle of Purbeck peninsula.

“We know the rays are not always there but we have no knowledge of where they go, how frequently they may visit the site, how far they may travel, whether they remain close by between sightings or whether they visit on occasional days as part of a much wider travelling pattern. Hopefully our information gathered from this site, and the possible identification of similar sites will complement other research studies and provide answers to some of these unknowns.”